Field of the Invention
The present invention relates to an elongate electrically conductive element comprising a core made of copper or copper alloy and at least one white-bronze layer, and to an electrical cable comprising at least one such an elongate electrically conductive element.
The present invention typically, but not exclusively, applies to low-voltage (especially lower than 6 kV) or medium-voltage (especially from 6 to 45-60 kV) power cables used in buildings, automobiles and in the field of rail transportation.
More particularly, the invention relates to an electrical cable having a good resistance to corrosion while guaranteeing good mechanical and electrical properties, especially in terms of temperature withstand and electrical conductivity.
Description of Related Art
A metal part (e.g. a high-frequency coaxial connector body made of brass) on which is deposited a copper layer then an anti-corrosion coating comprising a white-bronze layer is known from document EP 0 893 157A1, a palladium layer covering said white-bronze layer and a gold layer covering said palladium layer. White bronze is an alloy of copper and tin generally containing between 20 and 40% by weight tin. By virtue of this coating, said metal part is made resistant to corrosion while preserving a good solderability. However, the chemical composition of the white-bronze layer used is not described, the presence of a palladium layer and/or a gold layer on said part decreases its electrical conductivity, and the use of a gold layer as the outermost layer of the metal part decreases its deformation resistance. Furthermore, this metal part has the drawback of being very expensive because precious metals such as palladium and gold are used, and because of its manufacturing method, which requires a number of steps to form the various metal layers. Lastly, this metal part is not used to produce an electrical cable.